Signaling conductor



July 30, 1929. c. MARTELL SIGNALING CONDUCTOR Filed June 29, 1928 Patented July 30, 1929;

UNlTED? STATES mane Parana caries;

CHARLES MARTELL, OF CICERO, ILLINOIS, ASSIGNOR TO WESTERN ELECTRIC GOlVI- IPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK,

, srennmne connucron.

Application filed June 29,

case of submarine cables which are submerged in considerable depths of water, the mechanical stresses due to the great pressure of the water at such depths are sometimes suflicient to strain the magnetic loading material and unless precautions are taken to equalize these stresses they may materially aflect the magnetic characteristics of the loading material, thereby interfering with the proper transmission of intelligence over the cables. v i

It is the object of this invention to pro duce signaling conductors in which the mechanical stresses to which the conductors are subjected in use are equalized so that the operating characteristics of the conductors are not materially affected thereby.

In accordance with the general features of the invention, one specific embodiment thereof comprises a signaling conductor made of a conducting core and a magnetic material encircling the core and separated therefrom by a layer of a floating or cushioning material, such as stearine pitch, which is fluid at the temperatures and pressures under which the conductor is to be used, for example, sea bottom conditions.

The invention will be clearly understood from the following detailed description of a specific embodiment thereof, taken in connection with the accompanying drawing which illustrates that embodiment and in which the single figure represents a fragmentary, longitudinal view of a loaded signaling conductor with the successive layers thereof broken away to illustrate the construction ofthe interior of the conductor.

Experiments have shown that the magnetic characteristics of loading materials, such as those composed of magnetic alloys of nickel and iron, are materially affected when such materials are strained and that in signaling conductors loaded with these magnetic materialsstrains may be introduced 1928. Serial No. 289,093.

in' the magnetic materials as aresult of nonunlform pressure being applied thereto by the insulating material which surrounds the loading material, when pressure is applied to the insulating material by the .waterin which it is submerged. Experiments have also shown that if loaded signaling conductors are subjected topressure in such a manner as to impart a uniform pressure to the loading material, the magnetic characteristics of the loading material will not be materially affected;

In the present invention the tendencyof the loading material in a loaded signaling. conductor to be deformed by pressure under service 'conditons is overcome'by completely I filling the interstices between the loading material and the conducting core which it surrounds with a floating or cushioning material which isfluid at temperatures and 7 pressures commonly encountered in great depths of water. One material which gives very satisfactory results when employed as such a floating or cushioning'agent is stearine pitch, which is the residue obtained in the distillation of glycerine from materials produced in the manufacture of soap. 1

' In order to apply the stearine pitch in such a manner that all the interstices of the loaded conductor will be filled, it is desirable to use either a vacuum imprgnationor a' combination of a vacuum and pressure im,-

pregnation. In the first method the loaded conductor is conveyed through hot stearine pitch contained in a chamber which is maintained at a pressure less thanatmospheric pressure, whereby the air contained within the interstices of the conductor is withdrawn and replaced by the stearine pitch. It may also be desirable to convey the thus treated. conductor into a second container containing hot stearine pitch wherein a pressure in excess of atmospheric pressure is maintained to force the stearine pitch intothe interstices within the conductor. The conductor may then be withdrawn from the bath of hot compound and advanced through an extruding apparatus of any well known type, where it is covered with a layer or layers of a suitable insulating material, such as gutta perchaf A loaded signaling conductor made in ac: cordance with the invention is illustrated in the accompanying drawing, in which the numeral 10 designates a central solid copper Wire forming a part of a conducting core strips 11 in the form of a tape Wound closely in a spiral around the core, which loading material is preferably made of a magnetic nickel-iron alloy containing more than 25 per cent nickel, an alloy containing approximately 78 per cent nickel and the remainder principally iron having proven to give good results for this purpose. Surrounding the loading material 12 and filling the interstices between the loading material and the conducting core is a body 13 of stearine pitch forming a floating or cushioning agent Which tends to equalize pressures exerted upon the conductor and thereby prevent distortion of the loading ma terial. The loaded conductor and the floating material are surrounded by an insulating material 14:, such as gutta percha. The struc ture illustrated forms the core of the cable, which in addition may include protective materials, such as layers of jute, and armoring Wires to give additional mechanical protection.

While the invention has been described as applied to a loaded signaling conductor including a stranded conducting core, it is to be understood that the invention is not limited to this specific structure but may be applied With equal efi'ectiveness to signaling conductors having solid conducting cores.

What is claimed is:

1. A signaling conductor comprising a core, a magnetic material encircling the core, and a layer of stearine pitch separating the core and the magnetic material to prevent impairment of the magnetic'properties of the mag netic material by strains produced by high pressures.

2. A signaling conductor comprising a conducting core, a magnetic alloy ofnickel and iron encircling the core, and a layer of stearine pitch separating the core and the magnetic material to prevent impairment of the magnetic properties of the magnetic material by strains produced by high pressures.

3. A signaling conductor comprising a conducting core, a magnetic alloy of nickel and iron comprising about 78 per cent nickel and the remainder principally iron encircling the core, and a layer of stearine pitch separating the core and the magnetic material to prevent impairment of the magnetic properties of the magnetic material by strains produced by high pressures.

4. A signaling conductor comprising a composite conducting core, a layer of mag netic material disposed spirally therearound, and a layer of stearine pitch surrounding the magnetic material to equalize pressure exerted thereon.

magnetic alloy of nickel and iron comprising'about 78 per cent nickel and the remainder principally iron, a pressure equalizing material composed of stearine pitch.

In Witness whereof, I hereunto subscribe my name this 19th day of June. A. D. 1928.

CHARLES MARTELL. 

